9,299 research outputs found

    Study on needs for a magnetic suspension system operating with a transonic wind tunnel

    Get PDF
    The U.S. aeronautical industry was surveyed to determine if current and future transonic testing requirements are sufficient to justify continued development work on magnetic suspension and balance systems (MSBS) by NASA. The effort involved preparation of a brief technical description of magnetic suspension and balance systems, design of a survey form asking specific questions about the role of the MSBS in satisfying future testing requirements, selecting nine major aeronautics companies to which the description and survey forms were sent, and visiting the companies and discussing the survey to obtain greater insight to their response to the survey. Evaluation and documentation of the survey responses and recommendations which evolved from the study are presented

    Ames ER-2 ozone measurements

    Get PDF
    The objective of this research is to study ozone (O3) in the stratosphere. Measurements of the ozone mixing ratio at 1 s intervals are obtained with an ultraviolet photometer which flies on the ER-2 aircraft. The photometer determines the amount of ozone in air by measuring the transmission of ultraviolet light through a fixed path with and without ambient O3 present

    Equity markets, transaction costs, and capital accumulation

    Get PDF
    There is a close, if imperfect, relationship between the effectiveness of an economy's capital markets and its level (or rate of growth) of real development. This may be because financial markets provide liquidity, promote the sharing of information, or permit agents to specialize. There is literature about how these functions help increase real activity, but surprisingly little literature predicting how the volume of activity in financial markets relates to the level or efficiency of an economy's productive activity. The authors address this question: how does the efficiency of an economy's equity market -- as measured by transaction costs -- affect its efficiency in producing physical capital and, through this channel, final goods and services? The answer: As the efficiency of an economy's capital markets increases (that is, as the transaction costs fall), the general effect is to cause agents to make longer-term -- hence, more transction-intensive -- investments. The result is a higher rate of return on savings and a change in its composition. These general equilibrium effects on the composition of savings cause agents to hold more of their wealth in the form of existing equity claims and to invest less in the initiation of new capital investments. As a result, a reduction in transaction costs can cause the capital stock either to rise or fall (under scenarios described in the paper). Further, a reduction in transaction costs will typically alter the composition of saving and investment, and any analysis of the consequences of such changes must take those effects into account.International Terrorism&Counterterrorism,Economic Theory&Research,Environmental Economics&Policies,Payment Systems&Infrastructure,Banks&Banking Reform,Economic Theory&Research,Environmental Economics&Policies,Banks&Banking Reform,International Terrorism&Counterterrorism,Trade and Regional Integration

    Expressions to determine temperatures and emission measures for solar X-ray events from GOES measurements

    Get PDF
    Expressions which give the effective color temperatures and corresponding emission measures for solar X-ray events observed with instruments onboard any of the GOES satellites are developed. Theoretical spectra were used to simulate the solar X-ray input at a variety of plasma temperatures. These spectra were folded through the wavelength dependent transfer functions for the two GOES detectors. The resulting detector responses and their ratio as a function of plasma temperature were then fit with simple analytic curves. Over the entire range between 5 and 30 million degrees, these fits reproduce the calculated color temperatures within 2% and the calculated emission measures within 5%. With the theoretical spectra, similar expressions for any pair of broadband X-ray detectors whose sensitivities are limited to wavelengths between 0.2 and 100 A are calculable

    TALON - The Telescope Alert Operation Network System: Intelligent Linking of Distributed Autonomous Robotic Telescopes

    Full text link
    The internet has brought about great change in the astronomical community, but this interconnectivity is just starting to be exploited for use in instrumentation. Utilizing the internet for communicating between distributed astronomical systems is still in its infancy, but it already shows great potential. Here we present an example of a distributed network of telescopes that performs more efficiently in synchronous operation than as individual instruments. RAPid Telescopes for Optical Response (RAPTOR) is a system of telescopes at LANL that has intelligent intercommunication, combined with wide-field optics, temporal monitoring software, and deep-field follow-up capability all working in closed-loop real-time operation. The Telescope ALert Operations Network (TALON) is a network server that allows intercommunication of alert triggers from external and internal resources and controls the distribution of these to each of the telescopes on the network. TALON is designed to grow, allowing any number of telescopes to be linked together and communicate. Coupled with an intelligent alert client at each telescope, it can analyze and respond to each distributed TALON alert based on the telescopes needs and schedule.Comment: Presentation at SPIE 2004, Glasgow, Scotland (UK

    Interpenetration as a Mechanism for Liquid-Liquid Phase Transitions

    Full text link
    We study simple lattice systems to demonstrate the influence of interpenetrating bond networks on phase behavior. We promote interpenetration by using a Hamiltonian with a weakly repulsive interaction with nearest neighbors and an attractive interaction with second-nearest neighbors. In this way, bond networks will form between second-nearest neighbors, allowing for two (locally) distinct networks to form. We obtain the phase behavior from analytic solution in the mean-field approximation and exact solution on the Bethe lattice. We compare these results with exact numerical results for the phase behavior from grand canonical Monte Carlo simulations on square, cubic, and tetrahedral lattices. All results show that these simple systems exhibit rich phase diagrams with two fluid-fluid critical points and three thermodynamically distinct phases. We also consider including third-nearest-neighbor interactions, which give rise to a phase diagram with four critical points and five thermodynamically distinct phases. Thus the interpenetration mechanism provides a simple route to generate multiple liquid phases in single-component systems, such as hypothesized in water and observed in several model and experimental systems. Additionally, interpenetration of many such networks appears plausible in a recently considered material made from nanoparticles functionalized by single strands of DNA.Comment: 12 pages, 9 figures, submitted to Phys. Rev.

    Energetics and dynamics of simple impulsive solar flares

    Get PDF
    Flare energetics and dynamics were studied using observations of simple impulsive spike bursts. A large, homogeneous set of events was selected to enable the most definite tests possible of competing flare models, in the absence of spatially resolved observations. The emission mechanisms and specific flare models that were considered in this investigation are described, and the derivations of the parameters that were tested are presented. Results of the correlation analysis between soft and hard X-ray energetics are also presented. The ion conduction front model and tests of that model with the well-observed spike bursts are described. Finally, conclusions drawn from this investigation and suggestions for future studies are discussed
    corecore